Baseline characteristics by BMI group
| BMI group (n=385) | P values | |||
| Low | Normal | High | ||
| Total, n (%) | 20 (5.2) | 301 (78.2) | 64 (16.6) | |
| Sex, n (%) | ||||
| Male | 12 (5.9) | 175 (85.8) | 17 (8.3) | <0.001 |
| Female | 8 (4.4) | 126 (69.6) | 47 (26.0) | |
| Age, years | ||||
| Median | 12.8 | 10.1 | 10.7 | 0.005* |
| Range | 3.7–18.3 | 2.0–18.9 | 2.0–18.4 | |
| Ethnic origin, n (%) | ||||
| African | 16 (5.0) | 253 (79.1) | 51 (15.9) | 0.952 |
| Caribbean | 4 (6.8) | 43 (72.9) | 12 (20.3) | |
| Other | 0 (0) | 5 (83.3) | 1 (16.7) | |
| Genotype, n (%) | ||||
| HbSS | 17 (6.2) | 220 (80.6) | 36 (13.2) | 0.006** |
| HbSβ0 | 0 (0) | 5 (83.3) | 1 (16.7) | |
| HbSβ+ | 2 (13.3) | 9 (60.0) | 4 (26.7) | |
| HbSC | 1 (1.1) | 67 (73.6) | 23 (25.3) | |
| Chronic transfusions, n (%) | ||||
| Yes | 1 (3.7) | 21 (77.8) | 5 (18.5) | 0.910 |
| No | 19 (5.3) | 280 (78.2) | 59 (16.5) | |
| Sleep apnoea, n (%) | ||||
| Yes | 1 (1.8) | 45 (81.8) | 9 (16.4) | 0.493 |
| No | 19 (5.8) | 268(77.6) | 59(16.7) | |
*P value represents results from t-test for low versus normal BMI group.
**P value of HbSS versus HbSC only.
BMI, body mass index; HbSC, heterozygous haemoglobin; HbSS, homozygous haemoglobin.